package com.dries.security.app.authentication;

import cn.hutool.json.JSONUtil;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.collections.MapUtils;
import org.springframework.security.authentication.BadCredentialsException;
import org.springframework.security.core.Authentication;
import org.springframework.security.crypto.password.PasswordEncoder;
import org.springframework.security.oauth2.common.OAuth2AccessToken;
import org.springframework.security.oauth2.common.exceptions.UnapprovedClientAuthenticationException;
import org.springframework.security.oauth2.provider.*;
import org.springframework.security.oauth2.provider.token.AuthorizationServerTokenServices;
import org.springframework.security.web.authentication.SavedRequestAwareAuthenticationSuccessHandler;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.util.Base64;

/**
 * @Description:
 * @Author ZSY
 * @createTime 2020/9/4 10:34
 */
@Slf4j
@Component("driesAuthSuccessHandler")
public class DriesAuthSuccessHandler extends SavedRequestAwareAuthenticationSuccessHandler {

    @Resource
    private ClientDetailsService clientDetailsService;
    @Resource
    private PasswordEncoder passwordEncoder;
    @Resource
    private AuthorizationServerTokenServices authorizationServerTokenServices;

    private static final String GRANT_TYPE = "custom";

    @Override
    public void onAuthenticationSuccess(HttpServletRequest request, HttpServletResponse response, Authentication auth) throws IOException, ServletException {
        log.info("登录成功！");

        String header = request.getHeader("Authorization");

        if (header == null || !header.startsWith("Basic")) {
            throw new UnapprovedClientAuthenticationException("请求头中无Basic信息");
        }

        String[] tokens = this.extractAndDecodeHeader(header, request);

        assert tokens.length == 2;

        String clientId = tokens[0];
        String clientSecret = tokens[1];

        ClientDetails clientDetails = clientDetailsService.loadClientByClientId(clientId);

        if (clientDetails == null){
            throw new UnapprovedClientAuthenticationException("ClientId对应的配置信息不存在:" + clientId);
        } else if (!passwordEncoder.matches(clientSecret, clientDetails.getClientSecret())) {
            log.info(clientSecret + "================="  + clientDetails.getClientSecret());
            throw new UnapprovedClientAuthenticationException("ClientSecret不匹配" + clientId);
        }

        TokenRequest tokenRequest = new TokenRequest(MapUtils.EMPTY_MAP, clientId, clientDetails.getScope(), GRANT_TYPE);
        OAuth2Request oAuth2Request = tokenRequest.createOAuth2Request(clientDetails);
        OAuth2Authentication oAuth2Authentication = new OAuth2Authentication(oAuth2Request, auth);
        OAuth2AccessToken token = authorizationServerTokenServices.createAccessToken(oAuth2Authentication);

        response.setContentType("application/json;charset=UTF-8");
        response.getWriter().write(JSONUtil.toJsonStr(token));
    }

    private String[] extractAndDecodeHeader(String header, HttpServletRequest request) throws IOException {
        byte[] base64Token = header.substring(6).getBytes(StandardCharsets.UTF_8);

        byte[] decoded;
        try {
            decoded = Base64.getDecoder().decode(base64Token);
        } catch (IllegalArgumentException var7) {
            throw new BadCredentialsException("Failed to decode basic authentication token");
        }

        String token = new String(decoded, StandardCharsets.UTF_8);
        int delim = token.indexOf(":");
        if (delim == -1) {
            throw new BadCredentialsException("Invalid basic authentication token");
        } else {
            return new String[]{token.substring(0, delim), token.substring(delim + 1)};
        }
    }
}
